Greater Than 4-MHz Operation
Integrated Oscillator / Voltage Feed Forward
Compensation
>4:1 Input Voltage Range
25-ns Current Limit Delay
Programmable Maximum Duty Cycle Clamp
Optocoupler Interface
50-μA Start-Up Current
4.2-mA Operating Current @ 1 MHz
Smallest Footprint of the 8-pin MSOP
Package Minimizes Board Area and Height

description
The UCC35705 and UCC35706 devices are 8-pin voltage mode primary side controllers with fast over-current
protection. These devices are used as core high-speed building blocks in high performance isolated and non-isolated
power converters.
UCC35705/UCC35706 devices feature a high speed oscillator with integrated feed-forward compensation for
improved converter performance. A typical current sense to output delay time of 25 ns provides fast response to
overload conditions. The IC also provides an accurate programmable maximum duty cycle clamp for increased
protection which can also be disabled for the oscillator to run at maximum possible duty cycle.
Two UVLO options are offered. The UCC35705 with lower turn-on voltage is intended for dc-to-dc converters while
the higher turn-on voltage and the wider UVLO range of the UCC35706 is better suited for offline applications.
The UCC35705/UCC35706 family is offered in 8-pin MSOP (DGK), SOIC (D) and PDIP (P) packages.